Do Modafinil and Concerta interact?

Yes, it's a minor interaction but it's possible that the absorption of your modafinil may be delayed by an hour or so and you may not feel the effects as quickly.

Interactions between your drugs
Minor
methylphenidate modafinil
Applies to: Concerta (methylphenidate), modafinil

In single-dose pharmacokinetic studies, healthy volunteers given modafinil (200 mg) with dextroamphetamine (10 mg) or methylphenidate (40 mg) exhibited a delay in the absorption of modafinil by approximately 1 hour. The mechanism of interaction is unknown. No other alterations in the pharmacokinetics of any of the drugs were observed. Although not studied, the interaction is likely to also occur with the various prodrug, racemic, and enantiomeric formulations of these drugs (e.g., amphetamine, lisdexamfetamine, dexmethylphenidate, armodafinil).

https://www.drugs.com/interactions-check.php?drug_list=1647-0,1606-976&types%5B%5D=major&types%5B%5D=minor&types%5B%5D=moderate&types%5B%5D=food&types%5B%5D=therapeutic_duplication&professional=1