Tobacco use is the leading preventable cause of death in America and is elevated among patients with non-tobacco substance use disorders. Substance use treatment centers (SUTCs) do not commonly address their patients’ tobacco use. Lack of knowledge on treating tobacco use with counseling and medication may be a barrier that underlies this inaction. A multi-component tobacco-free workplace program implemented in Texas SUTCs educated providers on treating tobacco use with evidence-based medication (or referral) and counseling. This study examined how center-level changes in knowledge from pre- to post-implementation (i.e., over time) affected center-level behavioral changes in providers’ provision of tobacco use treatment over time. Providers from 15 SUTCs completed pre- and post-implementation surveys (pre N = 259; post N = 194) assessing (1) perceived barriers to treating tobacco use, specifically, a lack of knowledge on treating tobacco use with counseling or medication; (2) receipt of past-year education on treating tobacco use with counseling or medication; and (3) their intervention practices, specifically, the self-reported regular use of (a) counseling or (b) medication intervention or referral with patients who use tobacco. Generalized linear mixed models explored associations between provider-reported knowledge barriers, education receipt, and intervention practices over time. Overall, recent counseling education receipt was endorsed by 32.00% versus 70.21% of providers from pre- to post-implementation; the regular use of counseling to treat tobacco use was endorsed by 19.31% versus 28.87% from pre- to post-implementation. Recent medication education receipt was endorsed by 20.46% versus 71.88% of providers from pre- to post-implementation; the regular use of medication to treat tobacco use was endorsed by 31.66% versus 55.15% from pre- to post-implementation. All changes were statistically significant (ps < 0.05). High versus low reductions in the provider-reported barrier of “lack of knowledge on pharmacotherapy treatment” over time were a significant moderator of effects, such that SUTCs with high reductions in this barrier were more likely to report greater increases in both medication education receipt and medication treatment/referral for patients who use tobacco over time. In conclusion, a tobacco-free workplace program implementation strategy that included SUTC provider education improved knowledge and resulted in increased delivery of evidence-based treatment of tobacco use at SUTCs; however, treatment provision rates—in particular, offering tobacco cessation counseling—remained less than desirable, suggesting that barriers beyond lack of knowledge may be important to address to improve tobacco use care in SUTCs. Moderation results suggest (1) differences in the mechanisms underlying uptake of counseling education versus medication education and (2) that the relative difficulty of providing counseling versus providing medication persists regardless of knowledge gains.