argued october decided february sentencing reform act reform act eliminated special parole supervised parole commission drug offenders incarceration established conditions new system supervised release overseen sentencing however supervised release provisions effective date delayed november october abuse act adaa enacted sets minimum maximum sentences mandates terms supervised release certain drug offenses adaa sections specified november effective date petitioner convicted inter alia offenses applies occurred adaa enactment effective date reform act supervised release provisions district sentenced concurrent prison terms imposed concurrent terms special parole offense ruling congress intended parole imposed cases offenses committed interim adaa enactment november rejecting petitioner argument supervision appropriate offenses committed time appeals vacated sentence holding plain language required petitioner sentenced terms supervised release rather special parole held supervised release applies drug offenses categories specified adaa committed adaa enacted november pp section contains provision effective date therefore took effect date enactment clear direction contrary congress whose silence contrasts expression effective dates adaa sections nothing congress apparent purpose enacting rectify error controlled substances act required supervised release drug offenders rebuts presumption arguing congress must intended postpone penalty provisions order avoid creating conflict effective november authorize shorter sentences certain offenders cooperate government since mandatory minimum sentence requirements otherwise eliminate possibility shorter sentences offenses committed interim period petitioner mistaken congress corrected problems december permitting departures mandatory minimum sentences cooperating defendants whose offenses committed november move explained congress believed mandatory penalties gone effect adaa date enactment also rejected petitioner argument delayed implementation provides references special parole controlled substances act changed supervised release delayed effect supervised release provisions since specific provision controls one general application made change special parole supervised release independent general provision apply moreover unlikely congress intended delay provisions pp term supervised release defined enacted yet effective reform act rather adaa mean term used adaa significance november uncommon refer related legislative enactments interpreting specialized statutory terms device whose utility defeated fact act referred yet effective time adaa enacted reform act weight dignity deliberate considered enactment congress presented approved president reasonable assume congress passed adaa knew full definition supervised release existed reform act legislated reference also possible congress knowing unlikely anyone committing drug offense interim period released custody november concluded cases reform act effective time district began duties supervised release program section plain language also forecloses possibility rules governing special parole apply crimes committed interim period pp absence effective date provision create ambiguity calling invocation rule lenity may created minor inconsistencies statutory provisions supervision provisions ambiguous pp kennedy delivered opinion unanimous peter goldberger appointment post argued cause petitioner briefs pamela wilk amy wax argued cause pro hac vice brief solicitor general starr acting assistant attorney general mueller deputy solicitor general bryson richard friedman justice kennedy delivered opinion case presents problem interpretation federal drug enforcement laws reference method monitoring known supervised release drug offenders sentenced prison required serve terms special parole following incarceration sentencing reform act eliminated special parole place established conditions new system supervised release ensure orderly implementation change congress delayed effective date sentencing reform act supervised release provisions november year date however congress enacted abuse act adaa mandates terms supervised release certain drug offenses case consider whether adaa supervised release requirements apply offenses committed interim period adaa enacted sentencing reform act provisions supervised release became effective petitioner moshe convicted one count participation conspiracy distribute excess kilogram heroin counts distributing grams heroin possession intent distribute excess one kilogram heroin substantive offenses occurred february nearly four months adaa enactment eight months november effective date sentencing reform act provisions supervised release following remand third circuit reasons issue see levy en banc district sentenced petitioner years conspiracy count concurrent sentences substantive offenses sentencing hearing government petitioner disagreed whether form supervision required petitioner substantive offenses issue issue case us interpretation adaa codified supp iv although adaa specifies term supervised release government argued district term special parole required according government directs drug offenders receive supervision drug offenders sentenced special parole adaa enacted congress intended special parole imposed interim effective date sentencing reform act november petitioner contending congress intended delay effective date adaa supervised release provisions argued form supervision appropriate adaa offenses committed prior november district accepted government position imposed concurrent terms special parole petitioner substantive offenses third circuit vacated sentence remanded holding plain language petitioner sentenced two terms supervised release rather special parole according third circuit supervised release provisions became effective adaa date enactment october apply offenses committed date split among courts appeals appropriate form supervision interim period question granted certiorari affirm ii first trace detail relevant statutory history federal drug enforcement penalty scheme federal sentencing general begin controlled substances act tit ii stat codified first enacted subjected offenders involved manufacture distribution schedule ii narcotic substances including heroin maximum years imprisonment prison sentence imposed mandatory term special parole special parole period supervision served upon completion prison term administered parole commission bifulco see ed repealed tit ii stat part larger bill congress enacted two statutes altered penalty schemes federal drug offenders controlled substances penalties amendments act tit ii ch stat sentencing reform act tit ii ch ii stat controlled substances penalties amendments act increased maximum prison terms available controlled substances act offenses involving large quantities narcotic substances years provide term special parole offenses supp ii persons convicted crimes involving lesser amounts narcotic nonnarcotic substances remained subject penalties applicable offenses committed amendments including special parole thus increasing maximum terms imprisonment narcotics offenses amendments created peculiar situation offenders subject special parole offenders concurrent increases maximum penalties narcotics offenses sentencing reform act modified penalty scheme federal drug offenders deleting remaining references special parole version controlled substances act modification become effective november change reflected congress desire eliminate forms parole replace new system supervised release sentencing reform act provisions supervised release sentencing rather parole commission oversee defendant monitoring see terminate extend alter conditions term supervised release prior expiration event violation supervised release order hold defendant contempt decided upon supervised release preferred means monitoring congress nevertheless decided defer application drug offenses although sentencing reform act established conditions supervised release although act took step eliminating references special parole drug offenses congress take final step requiring supervised release persons sentenced controlled substances act step taken two years later congress enacted adaa stat adaa redefined expanded offense categories codified increased maximum penalties set minimum penalties many offenders adaa created new drug penalty classification offenses involving certain narcotics petitioner trafficking one kilogram heroin offenders narcotics crimes congress authorized sentences years life imprisonment supp iv violations involving grams one kilogram heroin congress authorized sentences years imprisonment violations involving schedule ii substances subject maximum years imprisonment penalties drug offenses remained mostly unchanged including mandatory special parole offenses involving relatively small amounts marijuana hashish house senate versions adaa original forms also required special parole terms imposed part package penalties major narcotics offenses see sess sess bills special parole provisions become effective immediately apply effective date new federal sentencing system november date house bill provided repeal special parole provisions senate bill provided references special parole changed supervised release see house bill senate bill neither alternatives adopted however instead final stages legislative process without explanation congress substituted words supervised release words special parole whenever latter term appeared see enacted congress adaa provides relevant part sentence subparagraph shall absence prior conviction impose term supervised release least years addition term imprisonment shall prior conviction impose term supervised release least years addition term imprisonment person sentenced subparagraph shall eligible parole term imprisonment imposed therein absence express deferral adaa effective date coupled delayed effective date sentencing reform act provisions governing supervised release created conflict interpretation among courts appeals persons affected interpretive problem whose offenses occurred october date adaa signed law november effective date sentencing reform act provisions supervised release majority courts appeals hold district case sentencing courts may impose supervised release crimes committed november instead require imposition terms special parole third circuit reversing district held supervised release applies offenses occurred october four circuits accept position least part government supports third circuit view petitioner still insists congress intended form supervision offenses committed november consider interpretations accords congressional intent iii well established absent clear direction congress contrary law takes effect date enactment see robertson bradbury arnold cranch see also singer sutherland statutory construction sands rev ed find contrary direction language evident purpose turning first text statute note like many congressional enactments contains provision effective date effective date specified adaa whole congress silence regard contrasts express effective date provisions discrete sections adaa see congress includes particular language one section statute omits another section act generally presumed congress acts intentionally purposely disparate inclusion exclusion russello internal quotations omitted see general motors anything discern congress purpose enacting rebut presumption became effective discussed controlled substances penalties amendments act inexplicably mandated supervision many drug offenders exempted narcotics offenders see supra section removed disparity mandated supervision schedule ii drug offenders given apparent purpose legislation rectify earlier mistake seems unlikely congress intended effective date time date enactment petitioner asks us look provisions adaa find congress intent first contends congress must intended postpone penalty provisions supervised release provisions november done otherwise created anomalies sections specifying effective date november authorize shorter sentences certain offenders cooperate government according petitioner became effective upon enactment possibility sentences mandatory minimum offenses committed period october november even though defendant otherwise qualified exception petitioner argument rejected every appeals consider likewise reject petitioner correct created minor anomalies congress recognized potential problems fixed december congress enacted legislation ensuring provisions permitting departures mandatory minimum sentences cooperating defendants apply offenses committed november see sentencing act stat corrective statute explained congress believed mandatory minimum penalties gone effect adaa date enactment october course view later congress establish definitively meaning earlier enactment persuasive value bell new jersey believe congress later enactment weighs petitioner favored reading statute petitioner next argues even adaa generally became effective date enactment read delayed effective date provision adaa delaying effective date supervised release provisions adaa well adaa provides remaining references special parole controlled substances act changed supervised release amendments made section take effect november plain meaning section refers entire adaa even one title chapter enactment rather refers general provision intended amend provisions controlled substances act retained term special parole november made change special parole supervised release independent adaa general provision including section delayed effective date apply specific provision controls one general application crawford fitting gibbons doubt moreover congress intend delay provisions supervised release make provisions effective determining meaning statute look particular statutory language design statute whole object policy crandon section grouped adaa penalty provisions imprisonment fines supervised release single paragraph new offense levels established supp iv unlikely third part penalty scheme postponed year first two took effect based review adaa say congress gave clear direction delay effective date supervised release provisions reviewed language structure adaa consider effect sentencing reform act provisions imposing revoking supervised release petitioner argues provisions become effective november term supervised release used adaa significance date courts power impose agree supervised release unique method supervision invented congress series sentencing reforms including drug offenders power duty impose supervised release explicit adaa enacted definition term supervised release set forth adaa set forth enacted though yet effective sentencing reform act early uncommon refer related legislative enactments interpreting specialized statutory terms see oscar mayer evans kokoszka belford northcross memphis bd education act referred later effective date defeat utility interpretational device courts may refer enacted yet effective legislation interpret statutory terms legislature intends reference time adaa enacted sentencing reform act though scheme yet operational weight dignity deliberate considered enactment congress presented approved president sentencing reform act origin specialized term supervised release adaa used term legislating upon subject matter reasonable assumption congress adopted adaa used term supervised release knew full definition existing sentencing reform act legislated reference see morissette plausible explanation disjunction statutes class defendants involved committed drug offenses october november great majority cases including case review likely offender released custody november date draftsman might well concluded cases sentencing reform act effective time district begin exercise duties supervised release procedures see slawsky looking law fed probation june reaching conclusion also reject holdings district courts appeals statutory provision imposing revoking supervised release go effect november rules governing special parole apply crimes committed interim period date plain language forecloses result see hallstrom tillamook county admittedly statutory scheme might appeared logical congress made last minute switch special parole supervised release however justify ignoring congress mandate term supervised release specific meaning reason doubt congress used term knowing differs term special parole intent sentencing courts follow direction statute hold offenses committed interim period october november supervised release applies drug offenses categories specified adaa finally petitioner invokes rule lenity contending absence effective date provision adaa creates ambiguity must construed favor see bifulco lewis believe however rule lenity applies rule comes operation end process construing congress expressed beginning overriding consideration lenient wrongdoers callanan applying principles statutory construction concluded congress use plain language intended narcotics offenders receive supervised release crimes committed october november may created minor inconsistencies statutory provisions provisions supervision ambiguous case involves ambiguity rule lenity resolve reasons set forth judgment appeals affirmed ordered footnotes statutes enacted part comprehensive crime control act tit ii stat lengthy piece legislation brought significant revisions many aspects federal criminal justice system including forfeiture bail procedures treatment juvenile mentally ill defendants drug offenses controlled substances penalties amendments act included involving grams heroin one kilogram cocaine grams lsd see supp ii enacted sentencing reform act provided elimination special parole terms take place november effective date amendments however many sentencing reform act key provisions delayed november see sentencing reform amendments act stat adaa prescribed equivalent thresholds mixture substance containing detectable amount illicit narcotics kilograms cocaine grams cocaine base grams phencyclidine pcp grams lsd grams propanamide kilograms marijuana see equivalent thresholds adaa mixtures substances grams cocaine grams cocaine base grams pcp grams pure gram lsd grams propanamide kilograms marijuana see mercado per curiam whitehead cert denied byrd paiz portillo per curiam levario smith cert denied see brundage app figueroa blackmon torres per curiam cert denied cf ferryman persons sentenced receive special parole offenses committed prior november see brundage supra charleus levy duprey cert denied padilla cert denied sub nom percheitte meyers garcia sections supp iv example petitioner contends congress switch special parole supervised release created inconsistencies penalty provisions controlled substances act specifically prohibits distribution drugs minors prohibits distribution drugs within feet school offenses committed prior november provide special parole terms multiples authorized section type quantity drug petitioner notes defendants charged crimes committed october november receive terms supervised release special parole enhancement provisions sections might apply assuming without deciding petitioner correct minor inconsistencies nevertheless sufficient overcome strong presumption favor october effective date congress possible lack attention collateral effects change special parole supervised release justify disregard change